Removal of catalyst from chloroprene by treatment with oxy acid

A process for manufacturing chloroprene comprising the steps of:

• (a) dehydrochlorinating 3,4-dichlorobutene-1 by reacting said 3,4-dichlorobutene-1 with aqueous alkali in the presence of an organic quaternary ammonium compound catalyst containing one or more quaternary ammonium groups wherein the quaternary ammonium cations are represented by the following structure
• R.sub.1 R.sub.2 R.sub.3 R.sub.4 N
• where R.sub.1, R.sub.2, and R.sub.3 are selected from the group consisting of a) cyclic or acyclic C.sub.7 -C.sub.20 alkyl radicals, C.sub.7 -C.sub.20 alkenyl radicals, C.sub.7 - C.sub.20 aralkyl radicals, and C.sub.7 -C.sub.20 aralkyl radicals having bonded thereto a C.sub.6 -C.sub.20 alkyl or alkenyl radical, and b) acyclic alkyl, alkenyl, or aralkyl radicals of up to 20 carbon atoms wherein a hydroxy or ether group is in a position beta or gamma to the nitrogen atom, and R.sub.4 is selected from the group consisting of C.sub.1 -C.sub.20 alkyl or aralkenyl radicals, and C.sub.7 -C.sub.20 aralkyl radicals, in one or more reactors, to provide a crude dehydrochlorination product and a chloride salt by product;
• (b) separating the crude dehydrochlorination product into an aqueous phase and an organic phase, said organic phase containing chloroprene and quaternary ammonium compound catalyst, and said aqueous phase containing substantially all of the chloride salt byproduct;
• (c) contacting the organic phase at a temperature of from about 0.degree.-60.degree. C. with at least 2 equivalents, per equivalent of quaternary ammonium compound catalyst, of an oxy acid selected from the group consisting of (i) inorganic acids containing at least one oxygen atom to which an acidic hydrogen is formally bound and (ii) polymeric resins having pendant inorganic oxy acid groups, the oxy acid being contained in a phase which is immiscible with said organic phase, thereby causing formation of a separate phase containing quaternary ammonium compound catalyst and oxy acid;
• (d) separating the phase containing the quaternary ammonium compound catalyst and the oxy acid from the organic phase containing chloroprene;
• and
• (e) recovering chloroprene containing a substantially reduced amount of quaternary ammonium compound catalyst.